1. Field of the Invention
The present invention relates to armaments and more particularly to guided munitions. More particularly, the invention relates to a system and method for optically guiding a munition following a ballistic path toward a target by processing optical signals from an optical source located at the target and controlling the roll of the munition to generate flight control signals fed to a plurality of flight control canards mounted on the munition.
2. Background Information
Mortars are one of the most commonly employed weapons in a ground combat unit. The traditional role of mortars has been to provide close and continuous fire support for maneuvering forces. Military history has repeatedly demonstrated the effectiveness of mortars. Their rapid, high-angle, plunging fires are invaluable against dug-in enemy troops and targets in defilade, which are not vulnerable to attack by direct fires. One of the major disadvantages of mortars is their comparatively low accuracy, and as a result mortars are becoming less effective in today's precision combat environment. Equipping a mortar round with a precision guidance package will increase its accuracy, enabling the mortar to be a precision munition that will be significantly more effective in wartime situations. For maximum utility, the guidance package preferably should be an inexpensive retrofit to current munitions, with a cost in production that allows its use in all situations, either as a guided or unguided weapon.
Unguided munitions are subject to aim error and wind disturbances. These often cause the munition to miss the target completely or require many rounds to complete the fire mission due to the large CEP (Circular Error Probability). Current approaches to guided weapons are expensive and are used on larger long range weapons. The approach of the present invention results in significantly lower cost and smaller size. This allows use with small to medium caliber weapons and significantly improves CEP which also results in a significant reduction in the quantity of rounds required to complete the fire mission which in turn results in lower overall cost and improved crew survivability. In addition, another benefit to this approach is the virtual elimination of collateral damage due to errant rounds impacting non-targeted areas.
Mortars, if guided at all, are guided by an expensive guidance and control (G&C) system. The cost is high for current guided mortars and unguided mortars have poor accuracy. Also, unguided mortars result in unacceptable collateral damage, excess cost due to large number of rounds required to blanket target area, and expose the mortar crew to counterbattery fire due to large time required to drop the necessary shells to saturate the target.
Existing prior art guidance systems and methods use algorithms that may be computationally inefficient, require excessive input information, are incompatible with new sensor designs and require expensive support hardware (seeker implementation).
Therefore, there is a need for an accurate and cost effective method for optically guiding munitions such as mortars. There is also a need for an ultra low cost G&C approach for mortars which is compatible with a large class of rounds. Furthermore, there is a need for a highly efficient detection/tracking algorithm compatible with optical hardware and limited processing capability associated with small caliber precision guided weapons design.